Tetrafluoroethylene hose is used in adverse applications wherein high resistance to temperature and chemical deterioration is necessary. Tetrafluoroethylene hose is increasingly employed in a wider variety of applications, and when the highest flexibility and resistance to flexing is desired, convoluted tetrafluoroethylene hose is utilized.
In the past, due to the characteristics of tetrafluoroethylene, hose end fittings of the reusable type were not usually employed. Rather, fittings employing swaged sockets are used to insure the necessary pressures required to produce efficient sealing. Such permanently mounted swaged end fittings require extensive hose inventories, and there has long been a need for a reusable fitting for use with convoluted tetrafluoroethylene hose which does not require special assembl apparatus, or unusual assembly skills.
It is an object of the invention to provide a fitting for convoluted tetrafluoroethylene hose wherein the fitting and components are reusable and may be assembled upon the hose without special skills thereby significantly minimizing hose and hose fitting inventories.
Yet another object of the invention is to provide a reusable fitting for tetrafluoroethylene hose of the convoluted type wherein effective sealing between the fitting and hose is readily accomplished, and sufficient mechanical interconnection therebetween is provided to resist fitting "blow off" under operating pressures.
Yet another object of the invention is to provide a reusable usable fitting for convoluted tetrafluoroethylene hose wherein the fitting components may be readily manufactured, and include a segmented socket for producing high radial sealing forces for compressing the hose upon a nipple, and wherein conventional tools may be employed by the installer permitting field assembl and disassembly.
A further object of the invention is to provide a fitting for convoluted tetrafluoroethylene hose utilizing a segmented socket wherein the fitting has a low profile and is of a concise configuration to meet aesthetic, safety and clearance conditions.
In the practice of the invention the fitting includes a tubular nipple having an inner end which is received within the bore of a convoluted tetrafluoroethylene hose. The outer end of the nipple is provided with conduit attachment structure, such as a nut.
The nipple inner end includes at least one annular ridge adapted to be received within a hose configuration, and a plurality of annular serrations are defined upon the nipple exterior surface for engagement with the hose interior surface. Also, the nipple is provided with a shoulder located adjacent the end of the hose forming a groove for receiving socket retention structure.
A segmented socket is mounted upon the nipple circumscribing the hose in radial alignment with the nipple inner end and threaded cap screws are used to radially compress the socket segments which consists of at least three identical cylindrical portion components. Cap screws circumferentially oriented to the annular configuration of the fitting interconnect adjacent socket segments for contracting the assembled socket and establishing a sealed relationship between the nipple inner end and hose by compression.
The socket segments are formed with a rounded protrusion of low profile which provides high strength characteristics and the cap screws are located within the maximum diametrical dimension of the protrusions in counterbored recesses and do not add significantly to the fitting diameter and profile permitting the fitting to be employed in concise locations.